There are many types of child resistant closure systems described in the art. An example of a particular type of child resistant closure system is proposed in U.S. Pat. No. 5,449,078, which relates to a combination of a container and safety cap. While many child resistant caps effectively provide protection against the danger of small children being able to remove potentially harmful contents, e.g. pills, from vials or other containers, they also provide a problem for a considerable portion of the adult population that require medication but lack the manual dexterity or strength to remove the child resistant cap. This is of a particular concern to the elderly population or people suffering from arthritis and other disabling diseases.
This particular problem has been addressed by the development of closure systems having a child resistant mode and a non-child resistant mode such that, in the non-child resistant mode, the closures are more easily opened by adults. Another example of such a closure is disclosed in U.S. Pat. No. 5,579,934, (the '934 patent). The '934 patent proposes a container closure that is selectively manipulatable between a configuration which resists opening by children and a configuration which may be easily opened without special manipulation of the closure. Specifically, the closure is manipulated into its non-child resistant mode by “pressing down” on the central portion of the top surface of the closure. Although the aforementioned closure provides an advance in the art of protection against the danger of small children being able to remove it from vials or other containers, a certain portion of the adult population lack the manual dexterity or strength to “press down” the central portion of the top surface of the closure so as to manipulate the closure from its child resistant configuration to its non-child resistant configuration. This manipulation or “pushing down” also represents a problem for people with long fingernails.
Other reversible or convertible child resistant closures have been proposed to address this problem. But making the closure easier to convert into the non-child resistant configuration increases the risk that the closures will inadvertently be converted into their non-child resistant configurations. Similarly, there is an increased risk that automated filling machines will inadvertently convert the closures into their non-child resistant configurations when applying the closure to the container.
Further, the closures of the type disclosed in the '934 patent cannot include a warning to the consumer once the closure has been converted to its non-child resistant configuration. This message is required by the Consumer Product Safety Commission (“CPSC”) to alert users that the closure has been converted into the non-child resistant configuration. Also, other reversible child resistant designs that do include the CPSC consumer warning cannot be used in automated dispensing equipment due to projections on their outer surface.
One problem in the art which is of particular concern is that where, out of inadvertence or neglect, a child resistant closure becomes partially closed, the child-resistant mechanism is not fully operative to the point that the child resistant container becomes susceptible to opening by children. One solution to this problem is to incorporate a positive lock mechanism or indicator to ensure that the child resistant mode is fully engaged whenever it is desired to do so.
Furthermore, in child resistant caps including two or more cap elements such as an inner cap element nested within an outer cap element equipped with an engaging device for rotatably coupling one cap element to the other, such as proposed in U.S. Pat. No. 4,520,938, the inventors herein have observed that where the outer cap is made of resilient material such as plastic, a risk exists that children could separate one cap from the other (“shelling”) thereby disabling the child resistance mode of operation. Once shelled, there is usually no other safeguard to prevent access to the contents of the container.
That is not to say, however, that purposeful shelling of a child resistant cap is undesirable. Indeed, it is also commercially desirable to have a child resistant cap assembly where the child-resistant means is incorporated only at the option of the consumer. One way to achieve this is to design a cap that is readily shellable by a person knowledgeable of how to easily shell the cap and which, when shelled, operates only in the non-child resistant position. In that way the outer shell or cap may also constitute a separate commercial item that can be used to convert an otherwise non-child resistant cap to a child-resistant cap.
In light of the foregoing, there is need for a closure and a container system that has a child resistant mode, has a non-child resistant mode which may be easily opened without special manipulation once a minimal torque threshold has been overcome, incorporates a positive lock mechanism to ensure that the child resistant mode is fully engaged, resists inadvertent conversion from its child resistant mode to its non-child resistant mode and still provides a fall back safeguard where that has been done, is capable of including the mandated CPSC warning “CAUTION NOT CHILD RESISTANT” when used in its non-child resistant mode, and can be used in automated dispensing machines thereby addressing the aforementioned deficiencies of the prior art.